Gradient-structure high-cobalt YG hard alloy for forming die and preparation method

The invention discloses a gradient-structure high-cobalt YG hard alloy for a forming die and a preparation method, trace TiN is added into the high-cobalt YG hard alloy, and a component gradient structure with no TiN phase on the surface layer and the TiN phase in the core part is formed in the sintering process of the hard alloy by utilizing the strong thermodynamic coupling effect between Ti and N. Before a hard alloy mixture is subjected to ball milling, the mixture is subjected to stirring-assisted ultrasonic dispersion homogenization treatment in advance, and TiN phase clusters in a hard alloy microstructure are reduced. The thickness of the gradient surface layer of the prepared gradient hard alloy is large enough, and surface oxide skin, microcracks and other surface defects can be removed through grinding machining. When being used as a forming die material, the material can resist plastic deformation of a forming die under the long-term impact effect in the using process and prevent the stability of